Stitching mechanism for sewing machines



4 J. E. cHALMAN.

STITCHING MECHANISM FOR SEWING MACHINES.

APRLIQATION men JAN-14, 1921.

Patented Nov. 28, 1922.

2 SHEETSSHEET I.

J. E. CHALMAN. STITCHING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED JAN. 14, 1921.

2 SHEETS-.SHEET 2- J/li/NNIE I N 26* atfoznegs Patented Nov. 28, 1922.

Patented Nov. 2&3, 1922.

the" and It JOlE-Ill EDWARD GHALMAN, OF CHICAGO, ILLINOIS, ASSIGNOR T0 UNION SPECIAL MACHINE COMPANY, OF CHICAGO, ILLINOIS, A CGBPORATION OF ILLINOIS.

STITCHING MECHANISM FOR SEWING MACHINES.

Application filed January 14, 1921.

To all whom it may concern:

Be it known that 1, JOHN E. CrIALMAN, a citizen of the United States, reslding at Chicago, in the county of Cook, State of Illinois, have invented certain new and useful Improvements in Stitching Mechanisms for Sewing Machines, of which the following is a description, reference being had to the accompanying drawing and to the figures of reference marked thereon.

The invention relates to new and useful improvements in stitching mechanisms for sewing machines, and more particularly to a stitching mechanism for making an interlocked seam, that is, a seam having a plurality of needle threads and a single looper thread interlocking and joining the needle loops of the several needles.

An object of the invention is to provide a stitching mechanism of the above character wherein the looper is provided with means for holding the needle thread loops thereon spaced so as to insure that the needles will enter the thread triangle ahead of the respective needle thread loops.

In the drawings which show by way of illustration one embodiment of the invention- Figure 1 is a front view of the machine embodying my invention;

Fig. 2 is an enlarged front view of the needles and the looper, showing more or less diagrammatically the position of the threads as the needles are descending and about to enter the thread triangle;

Fig. 3 is a plan view of the same, and,

Fig. 4 is a rear view of the looper.

The machine to which my invention is applied consists broadly of a work support 1, a supporting bed 2, an overhanging arm 3 in which the needle bar 4 reciprocates, and said needle bar 4: carries needles 5, 6 and 7 These needle are set abreast that is, in a line at right angles to the line of feed. The

feed dog is indicated at 8, and the presser foot which holds the material on the work support at 9. Cooperating with the needles beneath the work support is a looper 10 which is provided with the usual eye 11 through which the looper thread 12 passes. The looper is mounted on the looper carrier 13 pivoted at 14 to a looper rocker 15. The

looper is moved into and out of the needle Serial No. 437,215.

loops by means of a link 16 which is connected to the needle lever extension 17 of the needle lever 18. The looper rocker 15 is oscillated by means of an arm 19 which cooperates with an eccentric on the main shaft 20.

The looper, as clearly shown in the drawlngs, is provided with three notches 21, 22 and 23, respectively. These notches are formed on the rear and under side of the looper as shown more clearly in Fig. t. The needle threads for the needles 5 6 and 7 are lndicated respectively, at 241-, 25 and 26.

The general type of machine is well known in the art, and a description of the operation thereof is hardly thought necessary, except to state that the looper moves forward into all three of the needle thread loops entering the loop of the needle at the right, then the loop of the needle in the center, and then the loop of the needle at the left.

When the looper moves forward into the needle loops the needle loop of the righthand needle, as shown in Figure 2 will slip past the notches 22 and 23 and into the notch 21 and will lie in the portions of the notch both underneath the looper and in the rear face thereof. The needle thread loop of the middle needle 6 will slip past the notch 23 and into the notch 22 and lie in a similar manner therein while the needle thread loop of the needle '7 will lie in the notch 23. Without these notches on the looper, when the looper moves forward into a plurality of needle loops,there is a liability of the loops being brought together and being rolled together along the body of the looper and so interlocked as to prevent the separating of the loops when the looper moves rearwardly.

With my improved form of looper these needle thread loops will be spaced during the forward movement of the looper and will be retained in this spaced relation by the notches. The looper then moves laterally and rearwardly and as it moves laterally the respective needle thread loops will be moved out of the notched portions in the rear face of the looper but will be retained by the notched portions in the lower face of the looper. The continued rearward movement of the looper will draw the needle thread loops to the right, as viewed in Fig. 2,

so as to insure that each needle will enter its respective thread triangle in advance of or to the right of the corresponding needle thread loop, as viewed in Figures 2 and Having thus described the invention, What I claim as new and desire to secure by Let ters-Patent, is-- 1. A stitching mechanism for sewing Inachines including in combination, a plurality of needles set abreast, and a thread carrying looper'cooperating With all of the needles, said looper having separate means for each needle thread loop for temporarily retaining said needle thread loops thereon to insure that the needles will enter the thread triangle in advance of the respective needle thread loops.

2. A stitching mechanism for sewing machines including three needles, set abreast, a thread carrying looper cooperating With all three needles, means for moving the looper into and out of the needle thread loops, and means for moving the looper lat erally for giving the needle avoiding movement thereto, said looper having grooves formed in the body thereof disposed so as to receive and temporarily hold the respective needle thread loops so as to insure the points of the needles entering the thread triangle in advance of the respective needle thread loops.

In testimony whereof, I aflix my signature.

JOHN EDWARD CHALMAN. 

